Allergy is a disorder of the immune system that is inclusive of atopy. Allergic reactions occur in response to environmental substances known as allergens; these reactions are acquired, predictable and rapid. Allergy is characterized by excessive activation of certain white blood cells, called mast cells, and basophils by a type of antibody, known as IgE, resulting in an extreme inflammatory response. Common allergic reactions include eczema, hives, hay fever, asthma, food allergies, and reactions to the venom of stinging insects such as wasps and bees.
Different types of allergens are known. Inhaled allergens include dust or aerosols, e.g., pollen or house dust. Food allergens are substances contained in food to which the body reacts by hypersensitization (allergic reactions). Medicinal product allergens comprise certain active substances in medicinal products, for example antibiotics or analgesics. A particularly important group of allergenic substances are the contact allergens. These can cause an allergic reaction in those affected through skin contact. Certain metals and odoriferous substances belong among the contact allergens.
In recent decades, especially in the Western industrial countries a sudden rise in the number of allergens has been observed. Many allergenic substances are ingredients of cosmetics or other topically applied substances (compositions for local external application). Cosmetics or topical agents are tested for their allergenic properties by means of experiments on animals. The findings thus gained, however, are only of limited value because experimental animals do not always react to the same allergens as human beings and vice versa. This situation frequently gives rise to false positive and false negative results. Meanwhile there are also practical and ethical concerns associated with animal testing.
In light of the state of testing for allergenic activity, there is a need for effective new tools and methods for determining allergenic activity.